This document describes a methodology for estimating the performance of virtualized network functions (VNFs) in Network Functions Virtualization (NFV) environments, which aims to improve resource allocation and orchestration. It introduces a unified modeling approach that allows for mapping VNFs to various hardware platforms, thus enabling automatic performance estimation based on recurring execution patterns. The findings are validated through the modeling and performance evaluation of an Ethernet switch, showcasing the methodology's effectiveness in predicting maximum throughput.